The FreeBSD linux compatibility environment currently uses RPMs from Fedora 10. Unfortunately Fedora 10 is end of life since a while. For one of the RPMs (the pango one) we where aware of a security vulnerability. As we do not know if it is feasible to update the linuxulator ports to something more recent, I decided to setup a VM with Fedora 10 and generate a new RPM for the linux-f10-pango port. Thanks to Luchesar V. ILIEV for explaining me how to do this.
Setup of the VM
I used VirtualBox 4.0.4 on a Solaris 10 x86 machine. I configured a fixed size disk of 16 GB and kept the default network setup (after installing the guest tools / kernel modules I switched to virtio, as I was not able to do anything useful besides a ping) and RAM size. The CD/DVD drive was configured to use the image of the full Fedora 10 DVD for i386 systems.
Setup of Fedora 10
Booting the VM from the DVD leads to the graphical Fedora 10 install software (after chosing to install a new system on the console). There I accepted all the defaults, except for the software to install. I deselected the Office and Productivity group and selected the Software Development group. When I was asked if I want to install some additional RPMs I had a look at the complete list and installed some I thought are necessary. I do not remember anymore which ones I chose, but everything which looks related to RPM building is a good candidate.
After a while the install will be finished and you can boot into the new system (eject the DVD from the drive before reboot). After reboot chose to install the Guest Additions in the menu of the VM. This should mount the ISO image in the VM. As root execute the file for Linux. This will build some kernel modules for better integration (e.g. seamless integration of the mouse between your desktop and the VM). At this point I rebooted and configured virtio as the NIC. I also had to configure the network settings by hand, as the GUI tool did not safe all the settings correctly.
Update and install of required RPMs
After the VM was up and the network configured, I updated the entire system (chose System Update in the menu). To update the pango port, I had to install the libthai-devel RPM. I had the RPM for it (and all the files I need to build a new pango RPM) already downloaded, so I did a “yum install /path/to/rpm”. At this point I was ready to create the RPM build environment.
The RPM build environment
As a normal user I executed the command rpmdev-setuptree which creates the directory rpmbuild and populates it with some directories. Now you just need to find a suitable .spec file and put it into rpmbuild/SPECS, put the sources (and maybe patches referenced in the .spec file) into rpmbuild/SOURCES, and you are ready to go (I patched pango.spec for a more recent pango version, basically just changing the version numbers). If you want to have a custom packager and vendor attribute in the RPM, you can add a line for each to ~/.rpmmacros, e.g. %packager yournamehere and %vendor whateverisappropriate. I used my @FreeBSD.org EMail address as the packager, and FreeBSD as the vendor.
Building a RPM
I used rpmbuild ‑ba –target i386-redhat-linux-gnu –clean rpmbuild/SPECS/pango.spec to build the new pango RPM. If everything is OK, the resulting RPMs (a source RPM, a devel RPM, a debuginfo RPM and the RPM for the binaries) are in rpmbuild/RPMS and rpmbuild/SRPMS. For a FreeBSD port we just need the source RPM (to comply to the (L)GPL) and the RPM for the binaries.
The i386-redhat-linux-gnu string which is used for the –target option of the rpmbuild command is what seems to be used to build the Fedora 10 RPMs. After building pango, the RPM has i686-pc-linux-gnu in some filenames instead (the default value for this setup). The binaries seem to be compiled for i386, so there should be no problem even for old systems.